Electrostatic emission lens

An electrostatic emission lens arrangement for producing a microparticle image of a surface by means of charged particles emitted from said surface and accelerated to a predetermined final energy level, and comprising a first and a second apertured diaphragm electrode means arranged in spaced relationship with respect to each other and to said emitting surface, a voltage biasing source for producing a predetermined potential difference between said surface and the adjacently placed first apertured diaphragm electrode means, and a predetermined potential difference between said first apertured diaphragm electrode means and the second apertured diaphragm electrode means, said emitting surface (14) and the first apertured diaphragm electrode means (10) being spaced at a first distance (d.sub.1) and the first and second apertured diaphragm electrode means (10, 20) being spaced at a second distance (d.sub.2), and said spacing of said electrode means and the relationship between the potentials (V.sub.1, V.sub.2) of said surface (14) and of said first electrode means (10) being so dimensioned that the charged particles are accelerated between said surface (14) and said first apertured diaphragm electrode means (10) to a multiple of the desired final energy level, and that the particles are retarded to the desired final energy level when passing between said first (10) and second (20) apertured diaphragm electrodes means.